Still says 00 00 00 20, but it still reports 0x8 in NetBSD's debug
output.

Ok, the code that copies the data defaults to 8 if something goes
wrong while reading depth from OF and adding it to the device's
dictionary. Please have a look at dev/ofw/ofw_subr.c /
of_to_uint32_prop(), sprinkle a few printf()s so we can see where and
why it fails.